US5213397A - Freight brake control valve for railway cars - Google Patents
Freight brake control valve for railway cars Download PDFInfo
- Publication number
- US5213397A US5213397A US07/803,836 US80383691A US5213397A US 5213397 A US5213397 A US 5213397A US 80383691 A US80383691 A US 80383691A US 5213397 A US5213397 A US 5213397A
- Authority
- US
- United States
- Prior art keywords
- valve
- piston
- slide valve
- piston member
- release
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T15/00—Construction arrangement, or operation of valves incorporated in power brake systems and not covered by groups B60T11/00 or B60T13/00
- B60T15/02—Application and release valves
- B60T15/36—Other control devices or valves characterised by definite functions
- B60T15/42—Other control devices or valves characterised by definite functions with a quick braking action, i.e. with accelerating valves actuated by brake-pipe pressure variation
Definitions
- the present invention relates to pneumatic brake control valves for railway freight cars and particularly to an improvement thereof in terms of a release insuring feature.
- Control valve devices such as the well-known ABD type, employ a service valve assembly that is operable between brake release and application positions in accordance with the predominance of either brake pipe pressure that acts on one side of a piston member of the service valve assembly, or auxiliary reservoir pressure acting on the opposite side.
- the service valve assembly further includes a graduating valve that is carried by the piston member for direct movement therewith and a slide valve that is carried by the piston member with lost motion therebetween. Accordingly, relative motion exists between the graduating valve and slide valve during initial movement of the piston member in both the application and release directions, such relative motion effecting the valve connections as required to provide the various brake control functions of the service valve assembly.
- a bias force in the form of a leaf spring that acts laterally on the slide valve provides face-to-face sealing pressure at the interface of the slide valve and its seat in the slide valve bushing.
- the slide valve is also pressed to its seat by air pressure.
- This combined spring and air load on the slide valve causes frictional resistance to movement of the slide valve, which the piston member encounters through its lost-motion connection with the slide valve during initial movement from release position toward application position, and again during movement of the piston member from application position toward release position. In the latter instance, the piston member encounters this resistance of the slide valve at a location intermediate release and application positions to establish a lap position of the piston member in which the supply and release of brake pressure is cut off.
- This frictional resistance of the slide valve determines the differential force required to move the piston member from lap position to release position.
- this release differential corresponds to a 1.5 psi pressure differential by which the brake pipe pressure on one side of the piston exceeds the auxiliary reservoir pressure on the opposite side.
- This release differential is critical in terms of assuring a prompt release of the brakes on the cars of a train. It will be appreciated that the greater the release differential requirement to overcome the slide valve friction and effect movement of the piston member to release position, the greater the delay in effecting release of the train brakes. Factors that influence this frictional resistance include such variables as manufacturing tolerances, lap finish of the slide valve/bushing interfaces, wear of critical components, etc.
- the object of the present invention is to provide positive slide valve movement in response to a predetermined release pressure differential and thereby assure prompt release of a brake application on the cars of a train irrespective of such variables as influence frictional forces that resist slide valve movement.
- a control valve device comprising a housing, a first chamber in the housing connected to the brake pipe, a second chamber in the housing connected to the auxiliary reservoir, a piston valve assembly having a release position and an application position including a piston member between the first and second chambers movable in a first axial direction toward application position in response to a pressure differential between the first and second chambers in a first sense and movable in a second axial direction toward release position in response to a pressure differential between the first and second chambers in the opposite sense, valve means carried by the piston member for controlling the supply and release of braking pressure including a slide valve with which the piston member is engageable for effecting axial movement therewith in the second direction, and collapsible means between the piston member and slide valve for providing movement of the piston member in the second direction relative to the slide valve when the pressure differential in the opposite sense exceeds a predetermined
- FIG. 1 is a fragmentary, diagrammatic view showing the release position of a service valve assembly of a railway car control valve, as modified in accordance with the present invention
- FIG. 2 is a fragmentary, diagrammatic view showing the service valve assembly of the present invention in application position
- FIG. 3 is a fragmentary, diagrammatic view showing the service valve assembly of the present invention in lap position
- FIG. 4 is a fragmentary, diagrammatic view showing the service valve assembly of the present invention in initial release insuring position
- FIG. 5 is a fragmentary, diagrammatic view showing the service valve assembly of the present invention in final release insuring position
- FIG. 6 is a schematic view showing a railway freight car brake system including a control valve device in which the service valve assembly of FIGS. 1-5 is incorporated.
- a control valve device 30 which may be a well-known ABD/W type control valve modified in accordance with the present invention, is shown in FIG. 6 connected to the brake pipe 34 of a railway car (not shown).
- An auxiliary reservoir 39 is connected by piping to control valve device 30, as is a brake cylinder device 40 of the railway car.
- the air in auxiliary reservoir 39 is charged from the brake pipe during brake release and is supplied to the car brake cylinder 40 during a service brake application.
- An improved service valve assembly 1, various positions of which are shown in FIGS. 1-5, is employed in control valve device 30 and includes a service piston 2, a bushing 3 having a bore 4 in which piston 2 is operably disposed, a slide valve 5 having one face 6 engageable with an adjoining face 7 of bushing 3 that forms a slide valve seat, and a graduating valve 8 having a face 9 engageable with another face 10 of slide valve 5.
- pressure chambers 11 and 12 Formed on opposite sides of piston 2 are pressure chambers 11 and 12, the former being connected to the railway car brake pipe (not shown) via a passage 13 and the latter being connected to an auxiliary reservoir (not shown) via a passage 14.
- a stabilizing spring 15 is caged in the tail piece 16 of piston 2 between a spring guide 17 and a spring seat 18.
- Graduating valve 8 is carried fast in a recess 19 of piston 2, while slide valve 5 is carried in another recess 20 of piston 2, so as to have a lost-motion connection therewith.
- Spring guide 17 projects into recess 20 of piston 2 at the lower side of recess 21 and rests against a stop 22 in the piston tail piece. Being spring loaded, spring guide 17 is deflectable in an axial direction away from stop 22 upon engagement with slide valve 5 to provide the aforementioned lost-motion connection with piston 2.
- desired port connections at the slide valve/graduating valve interface are established during movement of piston 2 from release position toward application position and from application position toward release position.
- a further lost-motion connection between piston 2 and slide valve 5 is provided by a spring-loaded plunger 23 that is disposed in a cavity 23a of piston 2 and projects into recess 20 at the upper side 24.
- Plunger 23 rests against a stop 25 formed in piston 2 under the influence of a release insuring spring 26, which is caged under compression, as shown in FIG. 1.
- Plunger 23 is engageable with the upper side of slide valve 5 in lap position of piston 2 and is deflectable in an axial direction against the force of spring 26 when the slide valve friction becomes excessive, as shown in FIG. 4, the purpose being to establish a further port connection at the slide valve/graduating valve interface during the aforementioned lost-motion movement of piston 2 from lap position to release insuring position, for a reason hereinafter. explained in accordance with the present invention. .
- Slide valve 5 includes an application passage 27 and a release insuring passage 28, both of which extend between slide valve faces 6 and 10, and a connecting slot or groove 29 in face 6.
- An exhaust passage 31 in the control valve body is connected from slide valve face 7 to atmosphere, while a delivery passage 32 in the control valve body is connected from slide valve face 7 to a brake cylinder device (not shown).
- An exhaust passage 33 in the control valve body is connected from face 7 of bushing 3 to atmosphere.
- this exhaust passage 33 could be the quick service passage of the ABD/W control valve device, which serves to vent brake pipe pressure during initial movement of piston 2 from release to application position by means of passages in slide valve 5 and graduating valve 8 that have been omitted for the sake of clarity.
- a helical spring 35 that provides sealing force at the graduating valve/slide valve interface to prevent leakage of compressed air thereat.
- a leaf-type spring 36 between slide valve 5 and bushing 3 establishes a pressure seal at the slide valve/bushing interface.
- a roll pin 37 pivotally connects leaf spring 36 at its midpoint to a bifurcated lateral extension 38 of slide valve 5, in which the tail piece 16 of piston 2 is disposed for axial movement relative to slide valve 5 during lost-motion therebetween.
- leaf spring 36 bear against the inner diameter of bushing 3 under compression during axial movement of slide valve 5 with piston 2 following take-up of the aforementioned lost-motion therebetween, to establish and maintain the desired friction force with which face 6 of slide valve 5 engages face 7 of bushing 3 in order to provide the aforementioned pressure seal at the slide valve/bushing interface.
- a cover 41 encloses chamber 11 and provides a stop with which piston 2 is engageable to limit its upward travel and thereby establish service application position, as shown in FIG. 2.
- a spring seat 42 with which piston 2 is engageable to limit its downward travel and thereby establish release position, as shown in FIG. 1.
- Spring seat 42 abuts bushing 3 under compression of a spring 43 to normally maintain the spring seat location to establish this release position of piston 2, and deflects under a load greater than the force exerted by spring 43 to establish a retarded recharge position of piston 2 that forms no part of the present invention.
- the force exerted by spring 43 is generally sufficient to support a load on piston 2 corresponding to at least a predetermined pressure differential between chambers 11 and 12 at which movement of piston 2 from lap position (FIG. 3) to release position is intended to occur.
- this predetermined pressure differential known as the "release differential” is 1.5 psi.
- release insuring spring 26 is selected to deflect upon encountering a load in excess of 1.5 psi to ensure movement of piston 2 to release position at the desired "release differential", as will hereinafter be explained.
- slide valve 5 In release position of piston 2, as shown in FIG. 1, slide valve 5 is positioned by piston 2 acting through release insuring spring 26 and plunger 23 during the downward stroke of piston 2, so that slide valve application passage 27 is blanked by the graduating valve 8 at one end and by the slide valve seat in bushing 3 at the other end.
- delivery passage 32 is communicated with exhaust passage 31 via connecting groove 29 in slide valve face 6; and release insuring passage 28 is blanked at one end by graduating valve 8 and at the other end by slide valve seat 7 in bushing 3.
- venting delivery passage 32 to atmosphere via exhaust passage 31 it will be appreciated that the brake cylinder pressure is released in a manner well-known to those skilled in the railway braking art.
- chambers 11 and 12 are charged with compressed air from the brake pipe (not shown).
- Chamber 11 is charged directly via passage 13, while chamber 12 and thus the auxiliary reservoir (not shown) are charged via a charging choke and passage in slide valve 5, the charging choke and passage arrangement being well-known and understood by those skilled in the art, so that the showing of such has been omitted for the sake of clarity.
- graduating valve 8 uncovers application passage 27, which remains blanked at the slide valve/bushing interface until sufficient upward force is exerted by piston 2 to overcome the slide valve resistance.
- the slide valve 5 is shifted to its application position, as defined by engagement of piston 2 with cover 41.
- application passage 27 registers with delivery passage 32 to supply auxiliary reservoir pressure from chamber 12 to the car brake cylinder.
- release insuring passage 28 registers at one end with passage 33 at the slide valve/bushing interface, but remains blanked by the graduating valve at its other end.
- release insuring plunger 23 is displaced axially from the upper end of slide valve 5 a distance to assure that graduating valve 8 will cover the application passage 27, upon subsequent downward movement of piston 2 until release insuring plunger 23 engages the upper end of slide valve 5.
- Release insuring spring 26 is selected so that in its caged condition between piston 2 and plunger 23 the spring exerts sufficient force to overcome the normal resistance with which slide valve 5 resists movement of piston 2 without compressing. It will be appreciated, therefore, that in the case of slide valve 5 having normal frictional resistance, piston 2 and slide valve 5 move downward to release position, as shown in FIG. 1, as a unitary assembly, i.e., without any relative movement due to the absence of compression of spring 26.
- Auxiliary reservoir air in chamber 12 is thus connected from the cavity surrounding the piston tailpiece 16 to passage 33 leading to atmosphere.
- auxiliary reservoir pressure effective in chamber 12 is realized, thereby creating a sufficiently high pressure differential across piston 2 to overcome the abnormally high frictional resistance offered by slide valve 5.
- slide valve 5 Being in direct engagement with slide valve 5 in this initial release insuring position following take-up of the lost-motion between piston 2 and slide valve 5, the piston valve is conditioned to move as a unitary assembly from lap to final release insuring position, as shown in FIG. 5.
- slide valve connecting groove 29 in face 6 establishes registry between brake cylinder passage 32 and exhaust passage 31 to release the brake cylinder pressure, such brake release in accordance with the present invention being relatively prompt irrespective of such variables as slide valve friction that influence slide valve resistance and thus tend to delay piston actuation to release position.
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- Engineering & Computer Science (AREA)
- Transportation (AREA)
- Mechanical Engineering (AREA)
- Valves And Accessory Devices For Braking Systems (AREA)
Abstract
Description
Claims (12)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/803,836 US5213397A (en) | 1991-12-09 | 1991-12-09 | Freight brake control valve for railway cars |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US07/803,836 US5213397A (en) | 1991-12-09 | 1991-12-09 | Freight brake control valve for railway cars |
Publications (1)
Publication Number | Publication Date |
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US5213397A true US5213397A (en) | 1993-05-25 |
Family
ID=25187564
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US07/803,836 Expired - Fee Related US5213397A (en) | 1991-12-09 | 1991-12-09 | Freight brake control valve for railway cars |
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US (1) | US5213397A (en) |
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2013177489A1 (en) * | 2012-05-24 | 2013-11-28 | Wabtec Holding Corp. | Service main piston bushing containing two spring ramps |
US20150145323A1 (en) * | 2012-05-08 | 2015-05-28 | Wabtec Holding Corp. | Abdx-c service graduating valve and slide valve and slide valve design incorporating accelerated application valve (aav) functionality |
US9333959B2 (en) | 2012-04-03 | 2016-05-10 | Wabtec Holding Corp. | Brake cylinder maintaining valve |
US9925969B2 (en) | 2016-03-07 | 2018-03-27 | Westinghouse Air Brake Technologies Corporation | Cut-off valve and hot wheel protection valve arrangement |
CN108622061A (en) * | 2018-06-28 | 2018-10-09 | 眉山中车制动科技股份有限公司 | It extenuates and ensures valve and Pneumatic braking system |
US10647309B2 (en) | 2017-12-08 | 2020-05-12 | Westinghouse Air Brake Technologies Corporation | Quick Service Limiting Valve |
CN114834418A (en) * | 2022-05-13 | 2022-08-02 | 中车齐齐哈尔车辆有限公司 | Emergency valve with emergency acceleration relieving function |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2156720A (en) * | 1938-05-24 | 1939-05-02 | New York Air Brake Co | Air brake |
US4773713A (en) * | 1987-05-19 | 1988-09-27 | General Signal Corporation | Brake control system |
US4848849A (en) * | 1988-02-17 | 1989-07-18 | Werkzeugmaschinenfabrik Oerlikon-Buhrle Ag | Acceleration apparatus for connection with a pilot operated compressed-air brake |
US4974910A (en) * | 1989-08-14 | 1990-12-04 | American Standard Inc. | Freight brake control valve having improved quick service function |
US5071198A (en) * | 1991-01-22 | 1991-12-10 | Westinghouse Air Brake Company | Emergency valve for ABD freight brake control valve device |
-
1991
- 1991-12-09 US US07/803,836 patent/US5213397A/en not_active Expired - Fee Related
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2156720A (en) * | 1938-05-24 | 1939-05-02 | New York Air Brake Co | Air brake |
US4773713A (en) * | 1987-05-19 | 1988-09-27 | General Signal Corporation | Brake control system |
US4848849A (en) * | 1988-02-17 | 1989-07-18 | Werkzeugmaschinenfabrik Oerlikon-Buhrle Ag | Acceleration apparatus for connection with a pilot operated compressed-air brake |
US4974910A (en) * | 1989-08-14 | 1990-12-04 | American Standard Inc. | Freight brake control valve having improved quick service function |
US5071198A (en) * | 1991-01-22 | 1991-12-10 | Westinghouse Air Brake Company | Emergency valve for ABD freight brake control valve device |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US10556574B2 (en) | 2012-04-03 | 2020-02-11 | Wabtec Holding Corp. | Brake cylinder maintaining valve |
US9333959B2 (en) | 2012-04-03 | 2016-05-10 | Wabtec Holding Corp. | Brake cylinder maintaining valve |
US20150145323A1 (en) * | 2012-05-08 | 2015-05-28 | Wabtec Holding Corp. | Abdx-c service graduating valve and slide valve and slide valve design incorporating accelerated application valve (aav) functionality |
AU2013259567B2 (en) * | 2012-05-08 | 2017-02-02 | Wabtec Holding Corp. | A service valve portion of a brake control valve |
US9616872B2 (en) * | 2012-05-08 | 2017-04-11 | Wabtec Holding Corp. | ABDX-C service graduating valve and slide valve and slide valve design incorporating accelerated application valve (AAV) functionality |
RU2734736C1 (en) * | 2012-05-08 | 2020-10-22 | Уэбтек Холдинг Корп. | Braking distribution valve working valve part (versions) |
US9555790B2 (en) | 2012-05-24 | 2017-01-31 | Wabtec Holding Corp. | Service main piston bushing containing two spring ramps |
WO2013177489A1 (en) * | 2012-05-24 | 2013-11-28 | Wabtec Holding Corp. | Service main piston bushing containing two spring ramps |
US9925969B2 (en) | 2016-03-07 | 2018-03-27 | Westinghouse Air Brake Technologies Corporation | Cut-off valve and hot wheel protection valve arrangement |
US10647309B2 (en) | 2017-12-08 | 2020-05-12 | Westinghouse Air Brake Technologies Corporation | Quick Service Limiting Valve |
CN108622061A (en) * | 2018-06-28 | 2018-10-09 | 眉山中车制动科技股份有限公司 | It extenuates and ensures valve and Pneumatic braking system |
CN108622061B (en) * | 2018-06-28 | 2023-07-25 | 眉山中车制动科技股份有限公司 | Relief assurance valve and pneumatic compression system |
CN114834418A (en) * | 2022-05-13 | 2022-08-02 | 中车齐齐哈尔车辆有限公司 | Emergency valve with emergency acceleration relieving function |
CN114834418B (en) * | 2022-05-13 | 2023-08-11 | 中车齐齐哈尔车辆有限公司 | Emergency valve with emergency acceleration relief function |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: WESTINGHOUSE AIR BRAKE COMPANY A CORPORATION OF Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:TROIANI, VINCENT F.;REEL/FRAME:005942/0406 Effective date: 19911205 |
|
FPAY | Fee payment |
Year of fee payment: 4 |
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AS | Assignment |
Owner name: CHASE MANHATTAN BANK, THE, NEW YORK Free format text: SECURITY INTEREST;ASSIGNOR:WESTINGHOUSE AIR BRAKE COMPANY;REEL/FRAME:009423/0239 Effective date: 19980630 |
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Free format text: PAYOR NUMBER ASSIGNED (ORIGINAL EVENT CODE: ASPN); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
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FPAY | Fee payment |
Year of fee payment: 8 |
|
SULP | Surcharge for late payment |
Year of fee payment: 7 |
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REMI | Maintenance fee reminder mailed | ||
AS | Assignment |
Owner name: WESTINGHOUSE AIR BRAKE COMPANY, PENNSYLVANIA Free format text: TERMINATION OF SECURITY INTEREST RECORDAL STARTING AT REEL/FRAME 9423/0239.;ASSIGNOR:CHASE MANHATTAN BANK, AS COLLATERAL AGENT, THE;REEL/FRAME:012280/0283 Effective date: 20010501 |
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REMI | Maintenance fee reminder mailed | ||
LAPS | Lapse for failure to pay maintenance fees | ||
STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20050525 |